Acoustic measures for the assessment and analysis of phonatory functioning in various types of laryngeal pathology are being developed. Objective noninvasive assessment techniques which can differentiate between normal function and varying degrees of pathology have been completed. Various signal processing algorithms for analyzing frequency and amplitude components of speech waveforms are being evaluated for differential sensitivity to morphological and neurological changes in the larynx. Nasopharyngolarynscopic videotape recordings during connected speech are examined for interpretation of phonatory pathology in various types of disorders including spastic dysphonia and extrapyramidal disorders. Explanatory models of the effects of different laryngeal disease processes on phonatory function are sought to further understanding of the phonatory mechanism.